Proton-proton correlations in dp and 16Op interactions

Correlations between two protons emitted in dp and 16Op collisions at momenta 3.3 GeV/c and 52.6 GeV/c, respectively, are presented. The experimental data have been obtained using the one metre hydrogen bubble chamber exposed to nuclear beams from the synchrophasotron, JINR, Dubna. Data show a clear interference effect as expected for identical fermions. A Gaussian parametrization is used to determine the size of the proton emission source. The root mean square radius of the proton source calculated from the correlation function has been found to be equal to (2.10−0.35+0.43) fm and (2.67−0.38+0.54) fm for d and 16O respectively. It agrees with the known radii of these nuclei.

Asymptotic properties of multiplicity distributions in high-energy pn and pp interactions

Results of pn and pp multiplicity distributions from pd interactions at 400 GeV/c are presented together with others from 100–300 GeV/c. These, along with the corresponding distributions for pp interactions in a hydrogen bubble chamber were analysed to look into their scaling behaviour. It has been shown that neither the semi-inclusive scaling hypothesis nor the Mueller–Regge approach can explain the behaviour of data at 400 GeV/c. The subtraction of the leading particle did not seem to be effective. The charged multiplicities are shown to have a negative binomial distribution.

Multiplicity distributions in proton–neutron interactions at 400 GeV/c

We present a study on the charged multiplicity distribution in proton–neutron (pn) interactions at 400 GeV/c from the data on an exposure of a Fermilab 30-in. deuterium bubble chamber to 400 GeV/c protons. The pn and pp distributions were extracted through an empirical model to correct for double scattering in deuterium. The overall average fraction of the double scattered event is 0.128 ± 0.011. The resulting pn and pp multiplicity distributions give average multiplicities of 8.48 ± 0.10 and 8.99 ± 0.12 respectively. The fraction of pd events which occur off the neutron is 0.52 ± 0.02. The extracted pp distribution parameters are compared with those from the hydrogen bubble chamber (HBC) experiments. Distinctive features of extracted pn distribution are discussed.